Monohydroxyhydrocarbyl ureas as lubricating oil detergents



United States Patent 3,296,128 MONOHYDROXYHYDROCARBYL UREAS AS LUBRICATING OIL DETERGENTS Donald J. Anderson, San Anselmo, Califi, assignor to Chevron Research Company, a corporation of Delaware No Drawing. Filed Dec. 23, 1964, Ser. No. 420,817 6 Claims. (Cl. 25232.7)

This invention concerns novel hydroxyalkyl ureas and their use as additives in lubricating oils. More particularly, this invention concerns hydroxyalkyl ureas having alkylamino substi-tuents and their use as additives in lubricating oils.

Present day internal combustion engines operate at high speeds and high compression ratios. When used in the so-called city stop-and-go driving-the major type of driving conditions for a larger percentage of todays automobilesthe internal combustion engines do not reach the most efficient operating temperature. Under city driving conditions, large amounts of partial oxidation products are formed and reach the crankcase of the engine by blowing past the piston rings. Most of these partial oxidation products are oil insoluble, tending to form deposits on the various operating parts of the engine, such as the pistons, piston rings, etc. For the purpose of preventing the deposition of these products from the various engine parts, it is necessary to incorporate detergents in the lubricating oil compositions, thus keeping these polymeric products highly dispersed in a condition unfavorable for deposition on metals.

Under the harsh conditions of the engine-oxidative, acidic, trace metal catalysis-detergents undergo decomposition. It is therefore desirable to have detergents which are able to retain their detersive capabilitymain taining the polymeric materials in suspensionfor long periods of time.

Pursuant to this invention, N-fl-(hydroxy)alkyl-N'- aminoalkyl ureas are provided, wherein the monohydroxyalkyl group is of from 30 to 200 carbon atoms and the alkylamino group is of from 2 to 12 carbon atoms and from 1 to 5 nitrogen atoms. The total number of carbon atoms in the compounds of this invention will generally be in the range of about 35 to 210, more usually in the range of about 50 to 150. Generally, there will not be a single compound, but a mixture of compounds having average molecular weights or compositions with a few compositions predominating. The compounds of this invention find use as detergents in oils of lubricating viscosity.

For the most part, the compounds of this invention have the following formula OH wherein R is an alkyl radical of from 28 to 198 carbon atoms, more usually of from about 48 to 148 carbon atoms, Y is hydrogen or a lower alkyl group, T is an alkylene radical of from2 to 6 carbon atoms, more usually of from 2 to 3 carbon atoms, U is either hydrogen or lower alkyl, i.e., alkyl of from 1 to 6 carbon atoms, e.g., methyl, 'and x is a cardinal number of from 0 to 5.

A preferred group of compounds has the following formula Y R +omNHiiNHKO H2) yNHL1H OH wherein R is an alkyl radical of from about 48 to 148 carbon atoms, Y is as previously defined, x is :an integer of from 1 to 5, particularly of from 2 to 5, and y is an integer of from 2 to 3.

The compounds of this invention are prepared by adding a haloisocyanate across a terminal double bond, heating the resulting product in a suitable solvent to form the cyclic urethane and then treating the resulting urethane with an alkylene amine to form the desired mono hydroxyalkyl-alkylamine-substituted urea.

The addition of the haloisocyanate is readily carried out by adding in the presence of the monoolefin, silver isocyanate and halogen, particularly iodine. The resulting product may then be heated in the presence of a polar solvent, particularly a hydroxylic solvent, e.g., methanol, to provide the cyclic urethane or oxazolone. This product may then be treated with the desired alkylene amine, particularly at elevated temperatures to give the fin product.

The olefin used will generally be derived by polymerizing an olefin having from about 2 to 5 carbon atoms. Useful olefins are illustrated by ethylene, propylene, 1- butene, Z-butene, isobutene, l-pentene, and mixtures thereof, preferably isobutene.

The methods of polymerizing such olefins to the polymers of designated molecular weight are well known in the art and do not require exemplification here.

Illustrative polymers are polyisobutylene, polyethylene, polypropylene, polybutene-l, etc, all of the polymers being of from 30 to 200 carbon atoms.

The alkylene amines which are used have the following formula wherein T, U and x are as defined previously. Illustrative of various alkylene amines are ethylene diamine, diethylene triamine, triethylene tetramine, tetraethylene pentamine, pentethylene hexamine, di(tri-methylene) triarnine, hexamethylene diamine, N,N-dimethylpropylene diamine, etc.

The following examples are offered by way of illustration and not by way of limitation.

Example 1 Into a reaction flask was introduced 90.0 g. (0.6 mole) of silver cyanate, 457 g. (0.5 mole) of polyisobutylene, 500 ml. of ether and the mixture cooled to 5 C. A solution of iodine g., 0.5 mole) in 750 In. of ether was added over a period of 2 hours. The temperature was maintained at 5 C. for a further 18 hours while the mixture was stirred. At the end of this time, the silver iodide and any unreacted silver cyanate was filtered off, the filtrate divided into two parts, and 220 g. of a 100 neutral oil added to each portion. The ether was then removed by distillation. To the resulting oil solution was added 320 g. (10.0 moles) of methanol and the solution refluxed for one-half hour, at the end of which time the methanol was distilled off. To the product was then added 121 g. (0.064 mole) of tetraethylene pentamine (a mixture of alkylene amines having as their average formula and predominant product tetraethylene pentamine) :and the solution heated at 100 C. The temperature was raised to C. and maintained for 2 hours. 7

At the end of this time, the mixture was cooled and filtered.

Analysis.N. total 0.68, 0.70%; basic N, 0.25, 0.26%.

The compounds of this invention can be used with various base oils used as lubricating oils, such as naphthenic *base, parafiin base and mixed base lubricating oils. Other hydrocarbon lubricants such as synethetic oils, e.g., polyolefins, may be used. Also nonhydrocarbon lubricants, such as alkylene oxide type polymers, dicarboxylic acid esters, alkyl biphenyl ethers, silicates, etc.

The novel reaction products of this invention can be used in oils of lubricating viscosity in amounts of from 0.1 to 80 weight percent. When the oil is to be used in an engine, usually the amount of the detergent will be about 0.25 to 10 weight percent, more usually 0.5 to weight percent. However, because of the excellent compatibility of this inventions reaction products in oil, oil compositions may be prepared as concentrates, the concentrates having from to 80 weight percent of the active ingredients.

Generally, a metal thiophosphate will also be used in the oil. The preferred thiophosphates are zinc 0,0-dihydrocarbyl phosphorodithioate, wherein the hydrocarbyl group is of from 4 to 36 carbon atoms. (Hydrocarbyl is a monovalent organic radical composed solely of carbon and hydrogen which may be aliphatic, alicyclic or aromatic, or combinations thereof, e.g., aralkyl.) The amount of thiophosphate will generally be from about 5 to 50 millimoles per kilogram of the composition.

In addition to the dithiophosphate, the lubricating oil composition may also contain detergents other than those of this invention, viscosity index improving agents, rust inhibitors, oiliness agents, etc.

In order to demonstrate the excellence as detergents of the novel compositions of this invention, the composition of Example 1 was tested according to the Caterpillar L-l Supplement-1 conditions (MIL-L-2-1048, Supp. 1) for 120 hours. The composition of Example 1 was used in 2.5 weight percent in an SAE 30 solvent refined oil. The following table indicates the results.

1 The Grooves and Lands are evaluated on the basis of the deposits present. For the grooves, 0 is a clean groove; 100 is a groove full of deposits. For the lands, 0 is a clean land; 800 is a completely black land.

1 Also included in the oil composition was mM./kg. of Zn 0,0-di- (alkyl of from 4 to 6 carbon atoms) phosphorodithioate.

It is evident from the above table that the compositions of this invention provide excellent protection against polymeric deposition under extreme engine conditions.

As will be evident to those skilled in the art, various modifications on this process can be made or followed,

in the light of the foregoing disclosure and discussion, without departing from the spirit or scope of the disclosure or from the scope of the following claims.

I claim:

1. Compound according to the formula:

wherein R is an alkyl radical of from about 28 to 198 atoms, Y is lower alkyl, x is an integer of from 1 to 5 and y is an integer of from 2 to 5.

3. Compound according to claim 2 wherein R is polyisobutenyl, x is an integer of from 2 to 5 and y is an integer of from 2 to 3.

4. Compound according to claim 3 wherein x is 4 and y. is 2.

5. "A lubricating oil composition comprising from 0.1 to 80 weight percent of compounds accordingto claim 1. 6. A lubricating oil composition having from 0.1 to

10 weight percent of compounds according to claim 1 and from 5 to mM./kg. of the composition of zinc 0,0-dihydrocanbyl phosphorodithioate, 'wherein said hydrocarbyl group is of :from 4 to 36 carbon atoms.

References Cited by the Examiner UNITED STATES PATENTS 3,127,347 3/1964 Franz 252-515 X 3,133,883 5/1964 Hayne et a1 25251.5 3,219,666 11/1965 Norman et al. 25251.5 X

DANIEL E. WYMAN, Primary Examiner.

P. P. GARVIN, Assistant Examiner. 

1. COMPOUND ACCORDING TO THE FORMULA:
 6. A LUBRICATING OIL COMPOSITION HAVING FROM 0.1 TO 10 WEIGHT PERCENT OF COMPOUNDS ACCORING TO CLAIM 1 AND FROM 5 TO 50 MM./KG. OF THE COMPOSITON OF ZINC O,O-DIHYDROCARBYL PHOSPHORODITHIOATE, WHEREIN SAID HYDROCARBYL GROUP IS OF FROM 4 TO 36 CARBON ATOMS. 